So, why am I once more pulling on a costume I’m at the launch of the latest swimming technology from Speedo’s Aqualab in Nottingham. The new cossie has been four years in development, and it got wet for the first time during the 2012 London Olympics.

The new kit is rumoured to be able to give competitors — including British swimmers Rebecca Adlington and Liam Tancock — as much as a two per cent advantage over non-Speedo-wearing rivals, because this is not just a costume.

Breathe in: It takes Liz 35 minutes to squeeze into the Speedo costume

This is a Fastskin Super Elite Recordbreaker Kneeskin (the men’s version is called a ‘jammer’).

I won’t bore you with too much technology, but I will say the fabric (Pulse Power Hydro-K) is more tightly woven than ever before, with technology such as 3D compression, which transforms the body, any body, into a human torpedo, resulting in 16.6 per cent less drag, while oxygen economy is improved.

There is a ‘stability web’, which acts like a giant corset. And ‘fit point markers’, meaning you can tell if it’s on correctly (Olympic swimmers are nothing if not fiddlers, worrying about fit, so this new wheeze is vital).

Admittedly, I am nowhere near worrying if the Recordbreaker is on correctly, as currently it is still around my ankles. This is despite the fact I’ve had my bust, waist, thigh and trunk length measured (it comes in ten sizes).

I’m wearing the special white cloth gloves with rubber tips I need to pull it on (you need a vice-like grip), but it’s stubborn. I’m 13 years old again, feeling sticky and hot and fat.

This new costume takes, on average, 30 minutes to pull on, but apparently Britain’s Rebecca Adlington, can wriggle into it in six minutes flat. She should be given a gold medal just for that!

Eventually, a dresser supplied by Speedo joins me in my cupboard to help. We pull. We tug. We squeeze. We are now in a civil partnership.

Testing time: Liz heads to the pool to try out the costume in the water

Finally, after nearly 35 minutes, I am in. The results are amazing, like a super-expensive pair of Spanx (this costume costs 330, and Olympic swimmers wear them only once).

The shoulder straps hurt, though, and all the fat from my thighs is now seeping out around my knees. But I look like a swimmer. Almost.

Next, I have to wrestle on the swimming cap, part of a ‘trilogy’ (don’t you just love press release speak) of items that will apparently turn me into a human shark rather than a stone. The Speedo Fastskin cap (25), goes over a Speedo Fastskin Hair Management System (25).

Now, I could have done with these two water babies aged 13.

The HMS is pulled on, and I have to ease my hair into it, forming a sort of cone, like a cyclist’s helmet.

The cap goes on top, but despite all the years of research, it still feels like my mum’s flowery cap, giving me a red weal around my forehead, and a swimming headache. Ah well.

Next come the goggles, moulded using 3D laser technology: the distance between my irises is measured to get the right fit.

Unbelievably, even the psychology of swimming was investigated, at Loughborough University, in the making of these products.

Cutting edge: Rebecca Adlington wore the high-tech swimming suit to secure a bronze medal in the 400metre freestyle Olympic final

The result is a blue-grey tint on the goggles to instil a sense of calm and focus in swimmers, while the shape gives peripheral vision, important in keeping an eye on your rivals.

The trilogy are on show at the Design Museum in London as part of the Designed To Win exhibition, where you can also see Speedo’s LZR Racer ‘onesie’, which was famously worn by U.S. swimming phenomenon Michael Phelps, and was latterly banned after too many records were smashed.

Speedo tells me lots of research has gone into making ordinary women feel more confident about themselves (a Dove survey last week revealed 60 per cent of us avoid sport due to low self-esteem), and feel more inclined to take up swimming.

The results went towards producing the Speedo Sculpture Shapeline, the nearest thing available on the High Street to the made-to-measure Fastskin I’m in today, from 40.

It still reveals your arms and legs, unfortunately (I suppose the only answer is a burqini), but the effect on buttocks and tummy is magical.

This is all a very long way from the sort of costumes Speedo — founded by a Scot, Alexander MacRae, in Sydney in 1914 — first began making for the Olympics in the Twenties.

In those days, costumes were knitted from wool, which sagged rather when wet (nylon was only introduced in 1957).

But not everything has changed. In the 1932 Olympics in Los Angeles, Clare Dennis, the Australian swimmer who won the 200m breaststroke gold medal, was criticised by the Press for ‘showing too much shoulder’ in her revolutionary Speedo racer back.

Last week, Australian swimmer Leisel Jones was described by a newspaper as ‘out of shape’, accompanied by a deeply unflattering photograph.

Rebecca Adlington, too, has received abuse via Twitter about her appearance.

Looking at the competition swimmers modelling the new costumes at the launch, I can’t imagine a better physique to aspire to than that of a swimmer: broad shoulders, powerful thighs erupting from narrow hips, arms taut.

I wish now I’d not been put off swimming so profoundly as a child.

But just for today, in my Fastskin Recordbreaker, I am a human fish.

Streamlined: Bronze medalist Rebecca Adlington scythes through the water during the final of the women's 400-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park

Well, not quite, because as I lower myself gingerly into the pool at the Clissold Park Leisure Centre, in London’s Hackney, where I’m taking part in a Speedo swimming clinic ‘to hone my skills and knock vital seconds off my time’, I still reprimand the five-times world champion British swimmer James Hickman for splashing me.

Forty years on, little has changed regarding my levels of comfort in the pool.

I still hate being near people who are horsing around, and so resort to being dragged through the water holding on to a wooden pole for safekeeping. All I need now is a white polystyrene float.

It’s fair to say my ‘skills’ have not been improved and I certainly haven’t shaved any ‘vital seconds’ off my time although, in fairness, this is probably nothing to do with the suit and everything to do with me.

Designed To Win is at the Design Museum, Shad Thames, London, until November 18.